[doom1701]

I think the show does look different now than it did a couple of years ago. I think that it may something to do with him shooting the later episodes in hd.

There is also the changes to the set. They went from filming in a real kitchen (according to Wikipedia, Alton's mother in law's house), to a real kitchen in a house the producers built more or less for the show, to a more or less duplicate of that kitchen built on a soundstage. There is a different feel between the real kitchens and the set.

The show tends to be pretty experimental, so seeing a different filming method occasionally isn't surprising at all.